I went to a seminar and the guy pointed out the little white flecks as as fish. You could see they corresponded with the arcs on the sonar.
I'm interested to hear these comments too on the adjustments and settings. I just haven't taken the time to sit down and look at it that much. I know when I switch from 455kz to 800kz, the screen looks too dark. I'm sure it's a setting, I just need to set my rod down and play with the buttons.
I've always heard (and believed) you get a truer picture without fish symbols. The reason being, anything suspended in the water column (leaves, weeds, debris) shows up as a fish symbol. I also believe anything suspended in the water column will show up as an arc. Personally (I prefer arches) I think if you got away from the fish symbols and got comfortable not having them, you would learn to prefer it. However, if you really like the symbols stay with them. I don't think it's going to make or break a days fishing. Some folks put too much into it, it seems to me you do okay. I know your catching a lot more with those symbols than I am in my office.